In 2009, climate scientists reported that, without drastic action, human-induced global warming would soon reach a point of irreversibility. Despite this dire warning, and the hundreds of other scientific papers on climate change, even before 2009, the emission of greenhouse gasses continued to accelerate due to a failure to put in place sufficient preventative actions. One of the consequences of greenhouse gasses and thus higher temperatures is that megafires that are happening with increasing regularity around the world.

In Australia, the ongoing acceptance of wildfires, regardless of the ignition, has led to a dearth of understanding and leadership in wildfire prevention. Recognizing that wildfires are a mix of human-caused climate change as well as, often, human ignition, is vital to reducing the number and severity of wildfires.

An example of the need for prevention can be seen with the Dixie fire in California, which started on 13 July 2021, burnt 963,309 acres and was 94 per cent contained four months later. This outcome needed 6,579 fire fighters at the height of the fire and 1,792 miles of fire breaks created, the cost of firefighting reaching $USD610 million. Much of the burnt forest will not recover and will transition into a flammable shrubland.

The Californian fire agency reports that eight of the 20 largest fires recorded in that state were started by lightning, five were ‘human-related’, two were caused by powerlines and, for five of the fires, the cause was unknown. Determining the cause of wildfires such as the Dixie fire should involve a comprehensive evidence-based approach. Unfortunately, the current recording approaches (internationally) are not designed to assist future preventative action. They display variable recordings of the same type of ignition, at times based on little evidence or hearsay. Most fires are not recorded and many not officially investigated as to the cause, with few maliciously lit fires resulting in a conviction. All this results in large data gaps and often wide inconsistencies between data sets, even if they are covering the same geographical area.

Wildfire causation

A broad categorization of ignition causes may better assist fire prevention, thus avoiding the current tendency to explain many fires as ‘an accident’.